I would highly recommend a Revolut card. It's what most airline cabin crew use. It's app controlled, you load money straight from your bank or apple pay for example within the app. You can add funds in any currency, so when you know your bill (you can see it in your MDE account)and it was for example $1000 dollars, you don't need to work it out in to pounds, just add a $1000 and its available instantly. Saves adding more than you need, and money can stay in your bank earning interest. Any monies you leave on the card can be transferred back to your bank, or to another user, and all free to use. All card security is handled within the app too, you can disable card when not in use, and turn on or off online use, mag strip, contactless, and cash withdrawal et cetera. It has better exchange rates than credit cards and all high street bureau de change (and most online ones too) and can be used anywhere, it also has no charges or commission to move money around. We use it all over the world and when we stay at Disney, we just pay off whatever we've charged back to our rooms with it.